The Model EC 6 "Bismo-Count"
survey meter was built by Electronic Counter Laboratories Inc. at 418 South
Pecan St., Los Angeles California. It was primarily intended for uranium
prospecting.

The fact that it is called the Bismo-Count indicates that it
used a
Victoreen bismuth 6306 GM tube. Alas, the tube is missing in this example.
Even though the 6306 was more sensitive than Victoreen's 1B85 (used in ECL's
Electro-Count), the range of the Electro-Count and the Bismo-Count are the
same. They also employ the same count rate to exposure rate calibration (400
cpm = 0.1 mR/hr)